/*
* Conditions Of Use 
* 
* This software was developed by employees of the National Institute of
* Standards and Technology (NIST), an agency of the Federal Government.
* Pursuant to title 15 Untied States Code Section 105, works of NIST
* employees are not subject to copyright protection in the United States
* and are considered to be in the public domain.  As a result, a formal
* license is not needed to use the software.
* 
* This software is provided by NIST as a service and is expressly
* provided "AS IS."  NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
* AND DATA ACCURACY.  NIST does not warrant or make any representations
* regarding the use of the software or the results thereof, including but
* not limited to the correctness, accuracy, reliability or usefulness of
* the software.
* 
* Permission to use this software is contingent upon your acceptance
* of the terms of this agreement
*  
* .
* 
*/
/*******************************************************************************
* Product of NIST/ITL Advanced Networking Technologies Division (ANTD).        *
*******************************************************************************/
package gov.nist.javax.sip.header;

/**
 * Root class from which all SIPHeader objects are subclassed.
 *
 * @author M. Ranganathan   <br/>
 * @version 1.2 $Revision: 1.6 $ $Date: 2009/05/11 18:52:38 $
 *
 * 
 */
public abstract class SIPHeader
	extends SIPObject
	implements SIPHeaderNames, javax.sip.header.Header, HeaderExt {

	/** name of this header
	 */
	protected String headerName;

	/** Value of the header.
	*/

	/** Constructor
	 * @param hname String to set
	 */
	protected SIPHeader(String hname) {
		headerName = hname;
	}

	/** Default constructor
	 */
	public SIPHeader() {
	}

	/**
	 * Name of the SIPHeader
	 * @return String
	 */
	public String getHeaderName() {
		return headerName;
	}

	/** Alias for getHaderName above.
	*
	*@return String headerName
	*
	*/
	public String getName() {
		return this.headerName;
	}

	/**
	     * Set the name of the header .
	     * @param hdrname String to set
	     */
	public void setHeaderName(String hdrname) {
		headerName = hdrname;
	}

	/** Get the header value (i.e. what follows the name:).
	* This merely goes through and lops off the portion that follows
	* the headerName:
	*/
	public String getHeaderValue() {
		String encodedHdr = null;
		try {
			encodedHdr = this.encode();
		} catch (Exception ex) {
			return null;
		}
		StringBuffer buffer = new StringBuffer(encodedHdr);
		while (buffer.length() > 0 && buffer.charAt(0) != ':') {
			buffer.deleteCharAt(0);
		}
		if (buffer.length() > 0)
			buffer.deleteCharAt(0);
		return buffer.toString().trim();
	}

	/** Return false if this is not a header list 
	* (SIPHeaderList overrrides this method).
	*@return false
	*/
	public boolean isHeaderList() {
		return false;
	}

	/** Encode this header into canonical form.
	*/
	public String encode() {
		return encode(new StringBuffer()).toString();
	}

	public StringBuffer encode(StringBuffer buffer) {
		buffer.append(this.headerName).append(COLON).append(SP);
		this.encodeBody(buffer);
		buffer.append(NEWLINE);
		return buffer;
	}

	/** Encode the body of this header (the stuff that follows headerName).
	* A.K.A headerValue.
	*/
	protected abstract String encodeBody();

	/** Encode the body of this header in the given buffer.
	 * Default implementation calls encodeBody();
	 */
	protected StringBuffer encodeBody(StringBuffer buffer) {
		return buffer.append(encodeBody());
	}

	/** Alias for getHeaderValue.
	 */
	public String getValue() {
		return this.getHeaderValue();
	}
	
	/**
	 * This is a pretty simple hashCode but satisfies requirements.
	 * 
	 */
	public int hashCode() {
	    return this.headerName.hashCode();
	}
	
	public final String toString() {
		return this.encode();
	}
}
